Question

And sure enough, the following week there we were in front of this astonished stockbroker, and I was sitting there red-faced and quiet, and my mother, the real Mrs. Tan, was shouting at his boss in her impeccable broken English.

The inference suggested by this excerpt is that nonstandard forms of English
.

Answer 1

The inference is that nonstandard forms of English can still be skillful and effective—that they’re expressive and communicative, not necessarily inferior to standard English.